;------------------------------------------------------------
; File:  clay.l of clay of clos of lisp of ai

;------------------------------------------------------------
; Enter clos
;  ( in-package "pcl" )

;------------------------------------------------------------
; Classes

  ( defclass scanner
    () 
    ( ( token-line :accessor scanner-token-line
                   :initarg :token-line
      ) 
      ( token :accessor scanner-token
              :initarg :token
      ) 
      ( index :accessor scanner-index
              :initarg :index
              :initform 0
      ) 
    )
  )

  ( defclass parser
    () 
    ( ( scanner :accessor parser-scanner
                :initarg :scanner
                :initform ( make-instance 'scanner ) 
      ) 
      ( parse-tree :accessor parser-parse-tree 
                   :initarg :parse-tree
                   :initform '()
      ) 
    )
  )

  ( defclass processor
    () 
    ( ( parser :accessor processor-parser
               :initarg :parser
               :initform NIL
      ) 
      ( result :accessor processor-result
               :initarg :result 
               :initform NIL
      ) 
    )
  )

  ( defclass token
    () 
    ( ( name :accessor token-name
             :initarg :name
      ) 
      ( type :accessor token-type
             :initarg :type
      ) 
    )
  )


;------------------------------------------------------------
; The Token

  ( defmethod display-token ( (os t ) ( x token ) )
    ( princ "TOKEN...  " os )
    ( princ "name = " os )
    ( prin1 ( token-name x ) os )
    ( princ ";  " os )
    ( princ "type = " os )
    ( prin1 ( token-type x ) os )
    ( terpri os )
  )   


;------------------------------------------------------------
; The Scanner

  ( defmethod display-scanner ( (os t )( s scanner ) )
    ( write-string ">>>scanner ... " os ) ( terpri os )
    ( format t "token-line = ~A" ( scanner-token-line s ) os ) ( terpri os )
    ( display-scanner ( scanner-token s ) os )
    ( format t "index = ~A" ( scanner-index s ) ) ( terpri os )
    ( write-string "<<<scanner ... " os ) ( terpri os )
  )

  ( defmethod scan ( (os t)( s scanner ) ( parser-monitor-flag t ) &aux token)
    ( cond 
      ( ( >= ( scanner-index s ) ( length ( scanner-token-line s ) ) )
        ( setf token ( make-instance 'token :type 'end-of-stream ) )
      )
      ( t
        ( setf token ( elt ( scanner-token-line s ) ( scanner-index s ) ) )
        ( setf ( scanner-index s ) ( + ( scanner-index s ) 1 ) )
      )
    )
    ( setf ( scanner-token s ) token )
    ( if parser-monitor-flag ( display-token os ( current-token s ) ) )
  )

  ( defmethod current-token-type ( (s scanner) )
     ( token-type ( scanner-token s ) )
  )

  ( defmethod current-token-name ( (s scanner))
     ( token-name ( scanner-token s ) )
  )

  ( defmethod current-token ( (s scanner))
     ( scanner-token s )
  )

  ( defmethod reset-scanner (&aux s)
    ( setf s ( clay-scanner *clay* ) )
    ( setf ( scanner-index s ) 0 )
  )


;------------------------------------------------------------
; The Parser

  ( defmethod display-parser ( (os t) ( p parser ) )
    ( write-string ">>>parser ... " os ) ( terpri os )
    ( display-scanner os ( parser-scanner p ) )
    ( display-parse-tree os p )
    ( princ "<<<parser " os ) ( terpri os )
  )

  ( defmethod display-parse-tree ( (os t)( p parser ) )
    ( display-for-pt os 0 ( parser-parse-tree p ) )
    ;( terpri os )
  )


;------------------------------------------------------------
; The Processor

  ( defmethod display-processor ( (os t)( p processor ) )
    ( write-string ">>>processor ... " os ) ( terpri os )
    ( display-parser os ( processor-parser p ) )
    ( format t "result = ~A" ( processor-result p ) os ) ( terpri os )
    ( princ "<<<processor ... " os ) ( terpri os )
  )


  ( defmethod print-prefix ( (os t )( n number ) )
    ( if ( > n 0 )
      ( let ()
        ( princ "| " os )
        ( print-prefix os ( - n 1 ) )
      )
    )
  )